Emergency turning point?

[swissferry]

There is a very short gap in the armco on the M90. I presume it is an turning point for when the road is blocked. It is roughly mid way between junctions around 10 miles apart. The stretch between the junctions is steep and twisty in places for a UK motorway.

Can anyone confirm this is an emergency turning point or offer any other explanation?

Is there anywhere else such a short gap exists?

[jervi]

I don't think anyone could confirm its purpose 100%. By the looks of it those barrier along that section of the M90 have been there since about the 80s, and records + decisions for something like this likely do not exist.

The paved centre reserve bit, as you may know is a former crossover point, these used to be installed as part of the motorway standard, so many old motorways which haven't seen major works since their construction, these are still visible.
Other ones on this corridor have had a new barrier installed all the way across them, patching up the gap whilst still utilizing the original barriers.

The closing of gaps on the motorway network was completed in the shortly after 1990, so I imagine when this corridor was being assessed they left this one with a small gap for use in emergency situations, due to the otherwise limited access at junction 8 & for access to the bends you mentioned. It may or may nor have had anything blocking the gap initially, however GSV shows in 2009 that there were removable "wands" https://www.google.com/maps/@56.2889804 ... 312!8i6656
Which have now been replaced with non-removable flexi posts.
As the new posts are not removable, and don't flex left to right, it is now unfunctional as an emergency turnaround point. I imagine that it was assessed in 2009 when they needed to be replaced that the negatives outweighed the benefits to keep it open for emergency situations. Although the buried concreate terminus are still a massive hazard.

Alternatively, it was never intended as a turn around point when the gaps were closed, but due to underground services, they couldn't put in the foundations for the barrier posts, so they left a gap. This is quite unplausible as the edges of the carriageway has a barrier, plus underground services are usually so deep beneath a motorway that they wouldn't cause an issue with routine maintenance and minor changes such as this.

Are there any others?: On the motorway network, none that I can think of.

That is my take on it.

[KeithW]

A lot of motorways and dual carriageways had sections of easily removable Armco to facilitate turning round trapped traffic, the A14 certainly did as probably 20 years ago I used it after a major incident happened about 500 yards east of J35. As I recall an HGV had gone through the central reservation. We were turned back and had to take the parallel A1303 through Newmarket. There was another near Bar Hill as I recall.

Om the current A14 there are emergency slip roads facing east at J23 over the A1198.
https://www.google.co.uk/maps/@52.29223 ... 8192?hl=en


A more obvious example is the Conwy Tunnel where there is gated slip to let traffic turn around.
https://www.google.co.uk/maps/@53.28578 ... 6656?hl=en
https://www.google.co.uk/maps/@53.28598 ... 6656?hl=en

[Bryn666]

I don't think anyone could confirm its purpose 100%. By the looks of it those barrier along that section of the M90 have been there since about the 80s, and records + decisions for something like this likely do not exist.

The paved centre reserve bit, as you may know is a former crossover point, these used to be installed as part of the motorway standard, so many old motorways which haven't seen major works since their construction, these are still visible.
Other ones on this corridor have had a new barrier installed all the way across them, patching up the gap whilst still utilizing the original barriers.

The closing of gaps on the motorway network was completed in the shortly after 1990, so I imagine when this corridor was being assessed they left this one with a small gap for use in emergency situations, due to the otherwise limited access at junction 8 & for access to the bends you mentioned. It may or may nor have had anything blocking the gap initially, however GSV shows in 2009 that there were removable "wands" https://www.google.com/maps/@56.2889804 ... 312!8i6656
Which have now been replaced with non-removable flexi posts.
As the new posts are not removable, and don't flex left to right, it is now unfunctional as an emergency turnaround point. I imagine that it was assessed in 2009 when they needed to be replaced that the negatives outweighed the benefits to keep it open for emergency situations. Although the buried concreate terminus are still a massive hazard.

Alternatively, it was never intended as a turn around point when the gaps were closed, but due to underground services, they couldn't put in the foundations for the barrier posts, so they left a gap. This is quite unplausible as the edges of the carriageway has a barrier, plus underground services are usually so deep beneath a motorway that they wouldn't cause an issue with routine maintenance and minor changes such as this.

Are there any others?: On the motorway network, none that I can think of.

That is my take on it.

Snowploughs would be able to drive over those bollards, they're flexible hazardmaster types. I suspect there's a maintenance reason for this crossover and the guys to ask are probably the Scottish Roads Archive team!

As you all may or may not know, the catalyst for closing ECPs in 1989-90 was a horrendous incident on the M4 near Heathrow in 1987 involving a driver performing a U-turn. There had been other issues but this one resulted in fatalities. https://www.upi.com/Archives/1987/09/09 ... 558158400/

[Conekicker]

Yes, it's an emergency crossover point. "Filled" with the flexible posts to deter the hard of thinking but still usable in extremis. They are very rare nowadays for the reason Brynn stated.

[KeithW]

Alternatively, it was never intended as a turn around point when the gaps were closed, but due to underground services, they couldn't put in the foundations for the barrier posts, so they left a gap. This is quite unplausible as the edges of the carriageway has a barrier, plus underground services are usually so deep beneath a motorway that they wouldn't cause an issue with routine maintenance and minor changes such as this.

Are there any others?: On the motorway network, none that I can think of.

That is my take on it.

There are some on the A1(M) Darlington bypass such as here.
https://www.google.co.uk/maps/@54.49981 ... 6656?hl=en

It opened in 1965 and almost certainly would not have had a central barrier at that time. As I recall it was 1982 before the DfT issued the first standard for central barriers. Back then of course they used contraflows for road works with the only separation being traffic cones.

[wallmeerkat]

The A1 (NI) at the border has a crossing point, presumably for official/police traffic (eg. chases or giving an escort)
https://www.google.com/maps/@54.1142268 ... 384!8i8192

There is a no U turn sign https://www.google.com/maps/@54.1152251 ... 384!8i8192

As you can imagine, across the border the N1 side has similar https://www.google.com/maps/@54.1132316 ... 384!8i8192

With a mix of UK and Irish style No U turn signage https://www.google.com/maps/@54.1122517 ... 384!8i8192

[wallmeerkat]

Not so much a turning point as removable barrier, the A90 allows for the road to be diverted onto the old FRB if the Queensferry Crossing is closed https://www.google.com/maps/@55.9796634 ... 384!8i8192

Similar on the other end, old road coned to the left, removable barrier in the centre https://www.google.com/maps/@56.0180447 ... 384!8i8192

AFAIK this has been trial ran.

[Conekicker]

Not so much a turning point as removable barrier, the A90 allows for the road to be diverted onto the old FRB if the Queensferry Crossing is closed https://www.google.com/maps/@55.9796634 ... 384!8i8192

Similar on the other end, old road coned to the left, removable barrier in the centre https://www.google.com/maps/@56.0180447 ... 384!8i8192

AFAIK this has been trial ran.

That's Sologuard. There are quite a few installations on the motorway and trunk road network. Linky:

https://www.asset-vrs.co.uk/sologuard/

Given that the highway environment is an incredibly dirty place, the timing of just over 3 minutes shown on the video is optimistic to say the least. Absent frequent maintenance of the system, one might even say "brave". If you catch my drift.

[jnty]

Not so much a turning point as removable barrier, the A90 allows for the road to be diverted onto the old FRB if the Queensferry Crossing is closed https://www.google.com/maps/@55.9796634 ... 384!8i8192

Similar on the other end, old road coned to the left, removable barrier in the centre https://www.google.com/maps/@56.0180447 ... 384!8i8192

AFAIK this has been trial ran.

That's Sologuard. There are quite a few installations on the motorway and trunk road network. Linky:

https://www.asset-vrs.co.uk/sologuard/

Given that the highway environment is an incredibly dirty place, the timing of just over 3 minutes shown on the video is optimistic to say the least. Absent frequent maintenance of the system, one might even say "brave". If you catch my drift.

The closure for the trial run of this a few years ago was several hours, I think, so no bravery involved! Of course there's more to redirecting the course of a motorway than just fiddling with a barrier though.

[Conekicker]

Not so much a turning point as removable barrier, the A90 allows for the road to be diverted onto the old FRB if the Queensferry Crossing is closed https://www.google.com/maps/@55.9796634 ... 384!8i8192

Similar on the other end, old road coned to the left, removable barrier in the centre https://www.google.com/maps/@56.0180447 ... 384!8i8192

AFAIK this has been trial ran.

That's Sologuard. There are quite a few installations on the motorway and trunk road network. Linky:

https://www.asset-vrs.co.uk/sologuard/

Given that the highway environment is an incredibly dirty place, the timing of just over 3 minutes shown on the video is optimistic to say the least. Absent frequent maintenance of the system, one might even say "brave". If you catch my drift.

The closure for the trial run of this a few years ago was several hours, I think, so no bravery involved! Of course there's more to redirecting the course of a motorway than just fiddling with a barrier though.

Indeed there is. Although I rather suspect that if one of these things were ever opened in anger, it would be wise to have some cutting equipment to hand "just in case" the 1 in 1,000,000 chance inevitably happened, if only because the extra time taken to get such kit to site to do the necessary if/when it all went sufficiently pink wobbly ones up might cause questions to be raised in the House. Just saying like.

[orudge]

The A944 dual carriageway has had the former contraflow crossovers maintained following the construction of the A90 junction, with a load of plastic orange bollards installed. I’d assume if they wanted to close it off permanently they’d have installed something more substantial.

[Conekicker]

The A944 dual carriageway has had the former contraflow crossovers maintained following the construction of the A90 junction, with a load of plastic orange bollards installed. I’d assume if they wanted to close it off permanently they’d have installed something more substantial.

There are two ways to install traffic cylinders and they've picked the wrong one for that situation.

https://www.google.com/maps/@57.1472932 ... 384!8i8192

They've bolted surface mounted housings that the cylinders twist-fit into. Note how far above the carriageway surface the housing are, making them not safely trafficable in the event the crossover needs to be opened up for use - you'd have to remove the housings as well as the cylinders, which would take quite some time. Then to replace them when you no longer need to use the crossover, you'd have to put the housings back in slightly different locations, as the bolt holes wouldn't be suitable for re-use.

The right way to do it would have been to place cats-eye housings into the surface and then fit the cylinders into them - the cylinders are designed to do that. Then if you need to open the crossover, twist the cylinders out and pop a blank cats-eye rubber into the housing, to keep road dirt out. A quick task, especially compared to the other way of doing it.

You just can't get the staff these days.

[MotorwayGuy]

This crossover used to have such sockets, presumably for such posts. It was last used during parapet works in the mid 2000s, after which the corresponding one at the other end was removed but this one was retained for some reason.

I've never understood the purpose of this one though.

There is one with posts on the A2 near Eltham.

[wallmeerkat]

The A944 dual carriageway has had the former contraflow crossovers maintained following the construction of the A90 junction, with a load of plastic orange bollards installed. I’d assume if they wanted to close it off permanently they’d have installed something more substantial.

Are contraflows, particularly on motorways, still a thing? I've seen a lot of motorways have fairly permanent looking concrete barriers installed, and for work either use lane closures or full carraigeway closures and diversions. Seemed more of a thing in the 80s-90s?

[Big L]

Are contraflows, particularly on motorways, still a thing? … carraigeway closures and diversions. Seemed more of a thing in the 80s-90s?

No, no, no; they’re a modern innovation introduced in the last few years. Or so the authorities like to have us believe.

[Vierwielen]

The A1 (NI) at the border has a crossing point, presumably for official/police traffic (eg. chases or giving an escort)
https://www.google.com/maps/@54.1142268 ... 384!8i8192

There is a no U turn sign https://www.google.com/maps/@54.1152251 ... 384!8i8192

As you can imagine, across the border the N1 side has similar https://www.google.com/maps/@54.1132316 ... 384!8i8192

With a mix of UK and Irish style No U turn signage https://www.google.com/maps/@54.1122517 ... 384!8i8192

The Common Travel Area does not have the same rules as the Schengen area. In the latter, police who are in "hot pursuit" can legally drive up to 10km into a neighbouring [Schengen] territory and drag the miscreant back into their own territory.

[jnty]

The A944 dual carriageway has had the former contraflow crossovers maintained following the construction of the A90 junction, with a load of plastic orange bollards installed. I’d assume if they wanted to close it off permanently they’d have installed something more substantial.

Are contraflows, particularly on motorways, still a thing? I've seen a lot of motorways have fairly permanent looking concrete barriers installed, and for work either use lane closures or full carraigeway closures and diversions. Seemed more of a thing in the 80s-90s?

Contraflows are fairly routine on the M90 in my experience. Maybe they are generally less necessary on D3Ms.

[Chris5156]

The A944 dual carriageway has had the former contraflow crossovers maintained following the construction of the A90 junction, with a load of plastic orange bollards installed. I’d assume if they wanted to close it off permanently they’d have installed something more substantial.

There are two ways to install traffic cylinders and they've picked the wrong one for that situation.

Such a shame when the rest of the AWPR project was so well designed…

[Conekicker]

The A944 dual carriageway has had the former contraflow crossovers maintained following the construction of the A90 junction, with a load of plastic orange bollards installed. I’d assume if they wanted to close it off permanently they’d have installed something more substantial.

Are contraflows, particularly on motorways, still a thing? I've seen a lot of motorways have fairly permanent looking concrete barriers installed, and for work either use lane closures or full carraigeway closures and diversions. Seemed more of a thing in the 80s-90s?

Contraflows are fairly routine on the M90 in my experience. Maybe they are generally less necessary on D3Ms.

You only need a contraflow on a D2M if there's work in the nearside lane needs doing. Either that or, less ideal, a full closure. It's possible to do overnight or weekend closures if the work is fairly simple and can be quickly completed, even if in sections. Typically that means resurfacing.

On a D3M or more, narrow lanes is more common nowadays than contraflows. This has been the case for at least the last decade or more.

I honestly can't recall the last contraflow I designed, it was so long ago. There's nothing difficult to designing them, you just need to find crossover points in locations nearish to the works area, (and 200-300m clear of any slip road), where the level difference is close to zero. With the presence of concrete barrier these days, that's not as easy as it was with steel barrier.